A plating apparatus that performs plating processing of copper or the like sometimes adds an additive such as a promoter to a plating solution to provide uniform plating in a short time. For example, when copper serving as an interconnect material is embedded into spaces between fine patterns on a substrate as in a damascene method, additives such as an accelerator, a suppressor, and a leveler are added to a plating solution to grow copper in the spaces between the patterns in a short time while suppressing voids from occurring in interconnections. These additives are added to the plating solution when the concentrations thereof in the plating solution become lower than a predetermined value or periodically.
However, because the additives are decomposed into matters that hamper the plating processing as the time passes, bleed and feed (hereinafter, also “BF process”) needs to be performed when the amount of the plating solution has reached a predetermined level or periodically. The BF process of the plating solution is performed independently of addition of the additives and the BF process of the plating solution may be performed when the concentrations of the additives are high. In this case, the additives are drained wastefully by the BF process of the plating solution.